Auto merge of #4821 - aidanhs:aphs-allow-overflow, r=alexcrichton

Auto merge of #4821 - aidanhs:aphs-allow-overflow, r=alexcrichton

Remove overflow checks to eliminate rust build warnings

Although the checks are desirable, they cause warnings in the rust build (due to workspaces) which could cause needless concern. The checks aren't too important, so just disable them.

r? @alexcrichton (as discussed)